A motor vehicle is typically equipped with an engine mounting system to support the vehicle's engine on the body and to reduce transmission of engine vibrations to the passenger compartment. For effective reduction of engine vibrations a mount assembly is generally constructed from a rubber isolator sandwiched between a frame-mounted bracket and an engine-mounted bracket.
A vehicle engine has appreciable mass and inertia such that a frontal impact of sufficient intensity can cause the engine to move forward on its engine-mounts. If the impact force is sufficiently great, the mount components could disengage and fail. In cases where an engine is prevented by the mounting system from moving forward, a sufficiently high frontal impact load may drive the engine into the vehicle's passenger compartment. To prevent this, some engine-mounts are designed to disengage from the vehicle body and allow an engine to move forward in the vehicle, without regard to the force of the impact. Nevertheless, having an engine come off its mounts during a low-energy, i.e. low load, frontal impact, where the actual forces are insufficient to drive the engine into the passenger compartment, is likewise undesirable.
The present invention provides an engine-mount design for a motor vehicle that remains intact at low frontal impact loads, but also allows the engine to disengage from the vehicle body structure above a threshold frontal impact.